Exercise bike



FIG. 1 shows a front perspective view of an exercise bike;

FIG. 2 shows a front elevation view of the exercise bike of FIG. 1;

FIG. 3 shows a rear elevation view of the exercise bike of FIG. 1;

FIG. 4 shows a left elevation view of the exercise bike of FIG. 1;

FIG. 5 shows a right elevation view of the exercise bike of FIG. 1;

FIG. 6 shows a top view of the exercise bike of FIG. 1; and,

FIG. 7 shows a bottom view of the exercise bike of FIG. 1.

The broken lines illustrate environmental structure and form no part of the claimed design. 

CLAIM The ornamental design for an exercise bike, as shown and described. 